Development and validation of a simple and noninvasive method for salivary uric acid: potential applications for monitoring the salivary uric acid level in healthy volunteers and gout patients

Abstract Serum uric acid (UA) is a traditional biomarker in the clinical diagnosis of gout and hyperuricemia. However, serum treatment and storage are cumbersome, and wounds are susceptible to infection. Therefore, in this study, a simple and noninvasive method was developed to detect the UA in human saliva to monitor the gout. An Inertsil ODS-3 column was used for the analysis under the condition of isocratic elution with the mixed solution phosphate buffer (74 mM, pH=2.2): Methanol=98:2 (v:v) and the UV detection at 284 nm. Using salivary UA data from healthy volunteers (HVs) (n=68) and gout patients (GPs) (n=14), we examined the salivary UA difference in their content. The intra-and inter-day accuracy and precision (RSD %) were less than 2.56%, the limit of detection (LOD) of UA was 5.0 ng/mL, the mean recoveries of the corresponding compounds were 102.48%. Saliva levels of UA in HVs and GPs were 35.26±14.06 µg/mL and 91.96±23.90 µg/mL, respectively. The concentrations of salivary UA in GPs were significantly higher than those in HVs ( p < 0.001). This method was also expected to monitor the hyperuricemia and other metabolic disorders in the future

Effects of SphK1 gene on the proliferation and migration of colon cancer RKO cells induced by mesenchymal stem cells / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the effect of sphingosine kinase 1 (SphK1) knockdown on the proliferation and migration of colon cancer RKO cells induced by mesenchymal stem cells (MSCs). Methods: RKO cells were treated with MSCs conditioned medium (MSC-CM) or control medium (Control-CM), respectively. Cell proliferation was detected by CCK-8 assay. Cell migration ability was tested by Transwell chamber assay. The proteins expression of Ki-67, MMP-2/9, CD44 and CD133 was detected by Western blotting. Then, the expression of SphK1 in RKO cells was suppressed by targeted gene lentivirus shRNA vector transfection. The effects of SphK1 knockdown on the proliferation, migration and protein expressions of Ki-67, MMP-2/9, CD44 and CD133 of RKO cells induced by MSC-CM were observed. Results: The RKO cells proliferation was promoted by MSC-CM in a time-dependent manner; moreover (P<0.05), the migration ability of cells was significantly enhanced after being treated with MSC-CM(P<0.01). In addition, MSC-CM significantly increased the protein expressions of Ki-67, MMP-2/9, CD44 and CD133(all P<0.05 or P<0.01). Lentiviral ShRNA vector transfection could significantly inhibit the expression of SphK1. Down-regulation of SphK1 significantly inhibited the proliferation, migration and protein expressions of Ki-67, MMP-2/9, CD44 and CD133 of RKO cells induced by MSC-CM(all P<0.05 or P<0.01). Conclusion: MSC-CM promotes the proliferation and migration of colon cancer RKO cells. Down-regulation of SphK1 reverses the cell proliferation and migration induced by MSC-CM via inhibiting the expression of MMP-2/9, CD44 and CD133.